Mobility Modeling Flashcards
What is connected mobility?
Mobility + connectivity = time-variant topology
Differentiat Analytic and Realistic mobility models
Analytic: - allow performance evaluation
- parameter sweep for models in simulation
- models entities or entire systems
Realistic: - frequently used in simulations
- can be used in analytic studies
- agend-based simulations
Describe the role of limitations in human spartial activity
Human activity is mostly defined by limitations not by independent decisions.
Distinguish 3 travel behavior levels
- Strategic: choice of activities & order (going to work, shopping or taking a walk)
- Tactical: implementation of strategic decisions (means of transport)
- Operational: speed of walking, obstacle avoidance
Distinguish 3 different constraints on mobility
- Capabilities: biological or physical factors
- Coupling: need to be in a particular place at a given time
- Authority: control of access in compliance with rules
What levels of abstraction do we know in mobility modeling?
- Microscopic: capture individual behavior and interatcion; high detail level
- Macroscopic: Behavior of the entire system in aggregated form; individual cannot be distingushed from rest
- Mesoscopic: Group individuals with similar properties; compromise between analytical tractability and comp efficiency
What 6 features are used in simulating mobility?
- Spartial constrains: free, bounded, forbidden region, graph
- Pathfinding: biased random trip, on-the-fly, graph traversal
- Motion: random speed, collision avoidance
- Pause time: contant, random, regional
- Target selection: random trip, location bias, checkpoints, social network
- Group dynamics: reference target, internode forces
Describe how we can implement a location bias into a mobility model
Using the randowm waypoint model.
the bias can be introduced via 3 types
- static (time-invariant): city centers
- dynamic (time variant): events taking place
- social interest: probaility of goint somewhere depends how many friends are there
What are communities in random waypoint modeling and how can we implement them?
- split simulation area in a grid of comm.
- Each node has a home comm
- Assign different probabilities for picking next waypoint from home, gathering places or foreign comms
What are flaws of random waypoint?
- mean speed decays over time. Slow nodes take longer to reach dest; pause time adds up
- uneven node density distribution
Name 2 approaches to implement spartial constraints in a mobility model
- forbidden regions: obstacles or restricted areas
2. Graph constrained: movement only within edges and vertices
What is the reference point group mobility model?
One reference point per node. Reference points move into a common direction. Nodes follow their respective next point plus some oscillation around it.
Can be used to easily implement pursue (verfolgen) or nomadic community model
Describe human mobility
- regular re-apprearance at set of preferred locations
- Probability of returning to specific location is correlated with visitation frequency
- Power law jump size distribution
Spartial, temporal and social classes of characteristics.
How does the Work Day Movement Model work?
Staying home -> Working at office -> Activity w/ friends
transportation between activities
Works by having submodels for each activity
What are existing human mobility modeling approaches based on?
- Location preference
- Social relationships
- Agenda modeling
